Hmm, that's odd.
If that was the issue, you shouldn't be getting the "method not found (code-32601)" error; -snip-
Given the OPs location and comments, it is possibly related to the use of non-Latin characters (ie. Chinese) in the passphrase... and the way that the system is parsing it... TBH, I'm not surprised it might be something as simple as using ' instead of "...
Even so, if there's some something wrong with the passphrase and there's no quotation mark, the result should be the 'help' for walletpassphrase. Instead, he said it's "
method not found (code-32601)".
So I guess if it's the keyboard's fault, he may have used "
Pin Yin" when typing the
walletpassphrase command.